W DOC AIRBUS | TSM A320F

REGUL LO PR Indication with no Oxygen Pressure Value on the DOOR/OXY Page

TASK 35-10-00-810-820-A
REGUL LO PR Indication with no Oxygen Pressure Value on the DOOR/OXY Page

1. Possible Causes
  • C/B-OXYGEN/CREW/OXY/SPLY [1HT]
  • wiring from the circuit breaker (1HT) pin 2 to the first terminal block
  • XMTR/PRESS REG-OXY [4HT]
  • SOL VALVE-LP OXY SPLY [3HT]
  • P/BSW-OXYGEN/CREW SUPPLY (2HT)
  • short to ground at the wiring between the circuit breaker (1HT) pin 2 and the first terminal block
  • OXYGEN CYLINDER [5750HM1]
  • wiring
  • LP SOLENOID SUPPLY VALVE [3HT1]
  • OXYGEN CYLINDER [5750HM2]
  • PRESS.TRANSM.REGULATO [4HT2]
  • LP SOLENOID SUPPLY VALVE [3HT2]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 12-14-35-600-001
Servicing of the Oxygen-Replenishing
AMM 24-41-00-861-002
Energize the Aircraft Electrical Circuits from the External Power
AMM 31-60-00-860-001
EIS Start Procedure
AMM 35-11-41-000-802
Removal of the Crew Oxygen-Storage Cylinders
AMM 35-11-41-400-802
Installation of the Crew Oxygen-Storage Cylinders
AMM 35-13-00-00-
ASM 351301
AMM 35-13-15-000-001
Removal of the Oxygen Pressure Regulator/Transmitter
AMM 35-13-15-000-802
Removal of the Oxygen Pressure Regulator/Transmitters
AMM 35-13-15-400-001
Installation of the Oxygen Pressure Regulator/Transmitter
AMM 35-13-15-400-802
Installation of the Oxygen Pressure Regulator/Transmitters
AMM 35-13-51-000-001
Removal of the Low-Pressure Oxygen-Supply Solenoid-Valve
AMM 35-13-51-000-802
Removal of the Low-Pressure Oxygen-Supply Solenoid-Valves
AMM 35-13-51-400-001
Installation of the Low-Pressure Oxygen-Supply Solenoid-Valve
AMM 35-13-51-400-802
Installation of the Low-Pressure Oxygen-Supply Solenoid-Valves
3. Fault Confirmation
Subtask 35-10-00-860-067-A
A. Job Set Up
   (1) Aircraft Maintenance Configuration
     (a) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
     (b) Do the EIS start procedure (Upper ECAM DU and lower ECAM DU only)
AMM 31-60-00-860-001.
     (c) In the cockpit, on the OXYGEN section of the overhead control and indicating panel 21VU:
  • Push the CREW SUPPLY pushbutton switch (the OFF legend goes off).
Subtask 35-10-00-865-055-A
B. Make sure that this(these) circuit breaker(s) is(are) closed:
PANELDESIGNATIONFINLOCATION
** ON A/C ALL
49VUOXYGEN/CREW/OXY/SPLY1HTHA01
Subtask 35-10-00-710-069-A ** ON A/C NOT FOR ALL
C. Test
   (1) On the ECAM control panel:
  • Push the DOOR key to get the DOOR/OXY page:
   (2) Make sure that the REGUL LO PR indication comes into view and the oxygen pressure indication is replaced by amber crosses on the DOOR/OXY page.
   (3) If the circuit breaker (1HT) trips:
  • Refer to Para. 4.A.(2).
Subtask 35-10-00-710-069-B ** ON A/C NOT FOR ALL
C. Test
   (1) On the ECAM control panel:
  • Push the DOOR key to get the DOOR/OXY page.
   (2) On the DOOR/OXY page, make sure that:
  • A minimum of one of the two oxygen pressure indications is replaced with amber crosses, and
  • The REGUL 1 LO PR or REGUL 2 LO PR or REGUL 1+2 LO PR indication comes into view
( AMM 35-13-00-00-).
NOTE: The pressure indication given on the left side of the lower ECAM DU is for the Captain and the Third Occupant. The pressure indication given on the right side of the lower ECAM DU is for the First Officer and the Fourth Occupant.
4. Fault Isolation
Subtask 35-10-00-810-070-A ** ON A/C NOT FOR ALL
A. If the test confirms the fault:
  • do a check for the circuit breaker (1HT) status:
   (1) If the circuit breaker is closed
  • do a check for continuity between the circuit breaker (1HT) pin 2 and the first terminal block ASM 351301.
     (a) If there is continuity:
     (b) If there is no continuity:
  • repair the wiring from the circuit breaker (1HT) pin 2 to the first terminal block ASM 351301.
   (2) If the circuit breaker (1HT) is open:
  • close it.
     (a) If it trips:
       1 If the fault continues:
       2 If the fault continues:
  • replace the P/BSW-OXYGEN/CREW SUPPLY (2HT).
       3 If the fault continues:
  • do a check for a short to ground at the wiring between the circuit breaker (1HT) pin 2 and the first terminal block ASM 351301.
         a If there is a short to ground:
  • repair the above wiring.
         b If there is no short to ground:
     (b) If the circuit breaker is held closed and if the fault continues.
       1 If the fault continues:
       2 If the fault continues:
  • replace the P/BSW-OXYGEN/CREW SUPPLY (2HT).
Subtask 35-10-00-810-070-B ** ON A/C NOT FOR ALL
A. If the test confirms the fault on the Captain (and Third Occupant) oxygen system:
   (1) Do a check of the manual shutoff-valve position of the crew oxygen-storage cylinder (5750HM1).
CAUTION: WHEN YOU OPEN THE MANUAL SHUTOFF VALVE ON THE CREW OXYGEN-STORAGE CYLINDER, MAKE SURE THAT:
  • YOU TURN IT VERY SLOWLY
  • YOU TURN IT UNTIL IT IS FULLY OPEN.
IF YOU TURN THE MANUAL SHUTOFF VALVE TOO QUICKLY, YOU CAN CAUSE DAMAGE TO THE EQUIPMENT. IF THE MANUAL SHUTOFF VALVE IS NOT FULLY OPEN, THE OXYGEN PRESSURE DATA CAN BE INCORRECT.
     (a) If the manual shutoff valve is closed or not in the fully open position:
       1 Turn the manual shutoff valve in the fully open position.
       2 If the fault continues:
     (b) If the manual shutoff valve is in the fully open position:
   (2) If the fault continues:
     (a) Do a check of the pressure in the crew oxygen-storage cylinder (5750HM1) on its pressure gage.
       1 If the crew oxygen-storage cylinder (5750HM1) is not full:
   (3) Do a check for the circuit breaker (1HT) status:
     (a) If the circuit breaker (1HT) is closed:
  • Do a check for continuity between the circuit breaker (1HT) pin 2 and the first terminal block, ASM 351301.
       1 If there is continuity:
       2 If there is no continuity:
  • Repair the wiring from the circuit breaker (1HT) pin 2 to the first terminal block, ASM 351301.
     (b) If the circuit breaker (1HT) is open:
  • Close it.
       1 If it trips:
         a If the fault continues:
         b If the fault continues:
  • Replace the P/BSW-OXYGEN/CREW SUPPLY (2HT).
         c If the fault continues:
  • Do a check for a short to ground at the wiring between the circuit breaker (1HT) pin 2 and the first terminal block, ASM 351301.
* If there is a short to ground:
  • Repair the wiring.
* If there is no short to ground:
       2 If the circuit breaker stays closed and if the fault continues:
         a If the fault continues:
         b If the fault continues:
  • Replace the P/BSW-OXYGEN/CREW SUPPLY (2HT).
Subtask 35-10-00-810-090-A ** ON A/C NOT FOR ALL
B. If the test confirms the fault on the First Officer (and Fourth Occupant) oxygen system:
   (1) Do a check of the manual shutoff-valve position of the crew oxygen-storage cylinder (5750HM2).
CAUTION: WHEN YOU OPEN THE MANUAL SHUTOFF VALVE ON THE CREW OXYGEN-STORAGE CYLINDER, MAKE SURE THAT:
  • YOU TURN IT VERY SLOWLY
  • YOU TURN IT UNTIL IT IS FULLY OPEN.
IF YOU TURN THE MANUAL SHUTOFF VALVE TOO QUICKLY, YOU CAN CAUSE DAMAGE TO THE EQUIPMENT. IF THE MANUAL SHUTOFF VALVE IS NOT FULLY OPEN, THE OXYGEN PRESSURE DATA CAN BE INCORRECT.
     (a) If the manual shutoff valve is closed or not in the fully open position:
       1 Turn the manual shutoff valve in the fully open position.
       2 If the fault continues:
     (b) If the manual shutoff valve is in the fully open position:
   (2) If the fault continues:
     (a) Do a check of the pressure in the crew oxygen-storage cylinder (5750HM2) on its pressure gage.
       1 If the crew oxygen-storage cylinder (5750HM2) is not full:
   (3) Do a check for the circuit breaker (1HT) status:
     (a) If the circuit breaker (1HT) is closed:
  • Do a check for continuity between the circuit breaker (1HT) pin 2 and the first terminal block, ASM 351301.
       1 If there is continuity:
       2 If there is no continuity:
  • Repair the wiring from the circuit breaker (1HT) pin 2 to the first terminal block, ASM 351301.
     (b) If the circuit breaker (1HT) is open:
  • Close it.
       1 If it trips:
         a If the fault continues:
         b If the fault continues:
  • Replace the P/BSW-OXYGEN/CREW SUPPLY (2HT).
         c If the fault continues:
  • Do a check for a short to ground at the wiring between the circuit breaker (1HT) pin 2 and the first terminal block, ASM 351301.
* If there is a short to ground:
  • Repair the wiring.
* If there is no short to ground:
       2 If the circuit breaker stays closed and if the fault continues:
         a If the fault continues:
         b If the fault continues:
  • Replace the P/BSW-OXYGEN/CREW SUPPLY (2HT).
Subtask 35-10-00-810-091-A ** ON A/C NOT FOR ALL
C. If the test confirms the fault on the two oxygen systems:
   (1) Do a check of the manual shutoff-valve positions of the crew oxygen-storage cylinders (5750HM1) and (5750HM2).
CAUTION: WHEN YOU OPEN THE MANUAL SHUTOFF VALVE ON THE CREW OXYGEN-STORAGE CYLINDER, MAKE SURE THAT:
  • YOU TURN IT VERY SLOWLY
  • YOU TURN IT UNTIL IT IS FULLY OPEN.
IF YOU TURN THE MANUAL SHUTOFF VALVE TOO QUICKLY, YOU CAN CAUSE DAMAGE TO THE EQUIPMENT. IF THE MANUAL SHUTOFF VALVE IS NOT FULLY OPEN, THE OXYGEN PRESSURE DATA CAN BE INCORRECT.
     (a) If the manual shutoff valves are closed or not in the fully open position:
       1 Turn the manual shutoff valves in the fully open position.
       2 If the fault continues:
     (b) If the manual shutoff valves are in the fully open position:
   (2) If the fault continues:
     (a) Do a check of the pressure in the crew oxygen-storage cylinders (5750HM1) and (5750HM2) on their pressure gages.
       1 If the crew oxygen-storage cylinders (5750HM1) and (5750HM2) are not full:
   (3) Do a check for the circuit breaker (1HT) status:
     (a) If the circuit breaker (1HT) is closed:
  • Do a check for continuity between the circuit breaker (1HT) pin 2 and the first terminal block, ASM 351301.
       1 If there is continuity:
       2 If there is no continuity:
  • Repair the wiring from the circuit breaker (1HT) pin 2 to the first terminal block, ASM 351301.
     (b) If the circuit breaker (1HT) is open:
  • Close it.
       1 If it trips:
         a If the fault continues:
         b If the fault continues:
  • Replace the P/BSW-OXYGEN/CREW SUPPLY (2HT).
         c If the fault continues:
  • Do a check for a short to ground at the wiring between the circuit breaker (1HT) pin 2 and the first terminal block, ASM 351301.
* If there is a short to ground:
  • Repair the wiring.
* If there is no short to ground:
       2 If the circuit breaker stays closed and if the fault continues:
         a If the fault continues:
         b If the fault continues:
  • Replace the P/BSW-OXYGEN/CREW SUPPLY (2HT).
Subtask 35-10-00-710-070-A ** ON A/C NOT FOR ALL
D. Test
   (1) Make sure that the REGUL LO PR indication goes out of view and the oxygen pressure indication comes on on the DOOR/OXY page.
Subtask 35-10-00-710-070-B ** ON A/C NOT FOR ALL
D. Test
   (1) On the DOOR/OXY page, make sure that:
  • The REGUL 1 LO PR or REGUL 2 LO PR or REGUL 1+2 LO PR indication goes out of view, and
  • The two oxygen pressure indications come on.
5. Close-up
Subtask 35-10-00-860-068-A
A. Put the aircraft back to its initial configuration.
   (1) On the ECAM Control Panel, set the LOWER DISPLAY and the UPPER DISPLAY potentiometers to OFF.
   (2) In the cockpit, on the OXYGEN section of the overhead control and indicating panel 21VU:
  • Release the CREW SUPPLY pushbutton switch. The OFF legend comes on.
[Rev.8 from Aug 2018] 2026.04.04 04:33:37 UTC
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